Facebook patents that apply to React will also very likely also apply to Vue or any other virtual DOM library. Using Vue makes you more vulnerable, not less, since you no longer have the protection of the React.js patent grant.
You made this assertion before, but it's wrong and dangerous. Without knowing what the patents are, you cannot possibly say whether or not OTHER technology is infringing on it. It is especially bad considering you are not a lawyer, nor have professed any familiarity with the patent process.
It is a moderate, but known, amount of work to look through FB's patents, assess which are likely around React, and read through the claims. Considering it's possible, I certainly think that it's reasonable to ask you to do the work, or stop making the assertions.
"If you or your agent or exclusive licensee
institute or order or agree to the institution of patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that this implementation of Polymer or any code incorporated within this implementation of Polymer constitutes direct or contributory patent infringement, or inducement of patent infringement, then any patent rights granted to you under this License for this implementation of Polymer shall terminate as of the date such litigation is filed."
I dont see how is that similar to react. It makes way more sense and is closer in spirit to apache I think.
"If you or your agent or exclusive licensee institute or order or agree to the institution of patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that this implementation of Polymer or any code incorporated within this implementation of Polymer constitutes direct or contributory patent infringement, or inducement of patent infringement, then any patent rights granted to you under this License for this implementation of Polymer shall terminate as of the date such litigation is filed."
Polymer license only concerns itself with itself. FB license concerns all patents you and FB might have in addition to patents/righs concerning the react code itself.
There is a big difference, although it might not look like that.
"against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that THIS IMPLEMENTATION OF POLYMER or OR ANY CODE INCORPORATED WITHIN this implementation of Polymer".
I know I ask much of you but you can do it.
BTW. congratulations on copy pasting the text I pasted above...